A valve mechanism is the primary control element that controls the direction and volume of fluid flow in an intravenous (IV) infusion pump. Most valves operate through the application of an actuation force and a restorative force provided, for example, by a pump mechanism on a durable portion, to open and close a fluid pathway. Generally, a pump mechanism includes an actuation feature (e.g., mechanical “fingers”) that extends out to the valve located on a disposable portion. The actuation feature is used to pinch together two surfaces in a fluid path to close the valve. The actuation feature is retracted back to open the valve. For proper operation including complete closure of the fluid path, the actuation feature needs to be designed and built to a tight tolerance specification.
Tight tolerances on the design of a valve and an actuation feature generally increase the manufacturing cost of disposable and durable portions of an IV infusion pump. Therefore, it is desirable to use a valve mechanism that is less sensitive to design and manufacturing tolerances.